Media content is provided in many different formats. Many formats are not natively supported by various portable media players. Accordingly, such content is required to undergo a time-consuming conversion process to a supported format.
Typically, media content consists of media data and miscellaneous data. Media data includes audio and video streams. These streams are encoded using different codecs and packaged into different file containers. For instance, an AVI video (the file container format) may comprise a DivX encoded video stream and an MP3 encoded audio stream. The same streams can also be packaged into a MOV file container and appear as a different video to the portable media player.
Similarly, an audio stream may be encoded using different codecs and may be packaged into different file containers.
Therefore, to determine if media content is supported by and playable on a portable media player, the following components have to be considered:    1. File container—The portable media player must recognize the file container format before it knows how and where to parse the audio and video (for video content only) streams within the file.    2. Audio stream—The audio stream must be encoded using a codec supported by the portable media player in order for the portable media player to decode the audio stream. In addition, the portable media player may limit certain properties of the audio stream that it is capable of supporting. For instance, the sampling rate, the bit per sample, the number of audio channel and the bitrate of the encoded audio stream may be limited to suit the audio capability of the portable media player.    3. Video stream (for video content only)—The video stream must be encoded using a codec supported by the portable media player in order for the portable media player to decode the stream. In addition, the portable media player may limit certain properties of the video stream that it is capable of supporting. For instance, the dimension (width and height), the frame rate, the color depth and the bitrate of the encoded video stream may be limited to suit the video capability of the portable media player.
Previous attempts at simplifying and expediting the conversion process have had various degrees of success.
For example, iTunes 6 only allows video formats supported by the iPod to be downloaded to the iPod. Users are required to manually convert any unsupported formats before download. Only files listed in the iTunes video library can be selected for conversion. The files eligible for conversion are limited to those files that are supported by iTunes. Other video formats can be converted using an export function of QuickTime Pro or other third party software.
In another example, Windows Media Player 10 (WMP10) only permits video files from its Media Library to be downloaded to a portable media player. Therefore, file formats that are unsupported by WMP10 are excluded. While downloading to the portable media player, WMP10 automatically converts all WMV/ASF videos regardless of whether the formats are already supported by the Media Transfer Protocol (MTP) player. For other file types (for example, AVI), WMP10 copies them to the MTP player without conversion. There is no assurance that transferred files are playable in the MTP player.
Therefore, there is a desire to simplify and expedite the conversion process which ensures that the converted video or audio content is playable on a portable media player.